dt-bindings: hwmon: ltc2978: add support for ltm4673

Add LTM4673 to supported devices of LTC2978. Unlike other LTM46xx
devices, LTM4673 is a μModule regulator that outputs four channels.

Signed-off-by: Cedric Encarnacion <[email protected]>
Acked-by: Krzysztof Kozlowski <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Guenter Roeck <[email protected]>

Author: cencarna

Documentation/devicetree/bindings/hwmon/ltc2978.txt

@@ -22,6 +22,7 @@ Required properties:
   * "lltc,ltc7880"
   * "lltc,ltm2987"
   * "lltc,ltm4664"
+  * "lltc,ltm4673"
   * "lltc,ltm4675"
   * "lltc,ltm4676"
   * "lltc,ltm4677"
@@ -48,6 +49,7 @@ Valid names of regulators depend on number of supplies supported per device:
   * ltc3883 : vout0
   * ltc7841 : vout0
   * ltm4664 : vout0 - vout1
+  * ltm4673 : vout0 - vout3
   * ltm4675, ltm4676, ltm4677, ltm4678 : vout0 - vout1
   * ltm4680, ltm4686 : vout0 - vout1
   * ltm4700 : vout0 - vout1